For as long as television has been a commercially sponsored medium, advertisers of products have wanted to obtain information regarding time, market and frequency of broadcast. This information is often used to determine effectiveness of TV advertising or to validate content of signal transmissions. In order to maintain a high degree of accuracy this desired information has required until now manual collection by trained operators. Because of the enormous data contained within the video signal, approaches to electronic encoding of the video have presented limitations regarding practical storage capability and speeds of processing the incoming video.
Previous attempts to achieve automatic TV recognition were primarily designed to encode the audio component of the TV signal (see Lert, Jr. et al., U.S. Pat. No. 4,230,990 but rely on natural or synthetic media cues, e.g. . . . such as missing audio, increase in volume or highly compressed audio during passages of interest, broadcaster's fade to or from video black or "artificial" signals (such as inserted into the vertical blanking interval) by the TV station to trigger a time when to begin analyzing for a video passage of interest. Additionally, production effects or station changes to the video or audio signals (commercials or programming) differ from market to market and may violate copyright of the material. Media cues such as the broadcaster's program switches, or fades (such as to and from black) differ greatly from station to station and have been found reliable in only 90% of the time, at best.
Non-standard sources of video such as videotape or TV camera images are not suitable for systems developed to date, due to signal to synchronizing pulse instability.
Thus, this prior art provides no self-contained, efficient video apparatus or system for automatically monitoring or identifying passages of interest without modifying the TV signal, inserting media cues, or centrally-coordinating the databases of segments to deal with the problems described above.
Recently issued U.S. Pat. No. 4,739,398 of Thomas et al. entitled "Method and System for Recognizing Broadcast Segments", utilizes signatures derived from TV frames to recognize TV segments such as commercials. However, this system is relatively complex in its hardware and software, very expensive when compared to the invention described herein, and requires central comparison of collected signatures between several markets (using multiple samples) to provide accurate identification. The teaching of this patent has aspects which are useful in practicing the present invention and, to this extent, this patent is incorporated herein by reference.